PHOSPHATE ABSORPTION BY PLANTS FROM HABITATS OF DIFFERENT PHOSPHATE STATUS

SUMMARY Whole plants of Urtica and Deschampsia of different phosphate status were used to study phosphate uptake. By contrast with excised roots, the attached roots of the plants showed differences both in the rate of uptake and their patterns of incorporation of phosphate. The rate of phosphate absorption from low concentrations was rather similar for the two species, but from high concentrations, Urtica absorbed at a greater rate. A greater proportion of the absorbed phosphate was incorporated into acid insoluble and acid soluble organic phosphate in Urtica than in Deschampsia. Urtica is more sensitive to phosphate concentration in its total growth rate relative shoot and root growth, and in total uptake than Deschampsia .